This invention relates to an improvement of apparatus for resecting objective regions inside the body cavity by means of high-frequency currents.
In general, an apparatus for resecting celiac tissue, such as polyps, by means of high-frequency currents employs a system to resect a region inside a body cavity suffering a polyp by applying a high-frequency current between an electrode for resection formed of a looped conductive wire inserted into the body cavity and an external electrode in wide contact with the external surface of the human body which is formed separately from the resection electrode. According to such conventional system, however, the high-frequency current, which is caused to flow through the interior of the body, may bring about cauterization of some other regions of the body than the objective region, frequently causing perforation in unexpected parts of the body or, in case of poor contact between the external electrode and the surface of the body, burns.
Hereupon, there is known an alternative system to apply a high-frequency current between two conductive wires to serve as electrodes of different polarities whose tip ends are coupled to each other with an insulating material between, forming a loop. In this system, however, even if the neck of the polyp is wrung by the loop and supplied with current, the portion touching the insulating material may be left uncauterized, leading to the fear of bleeding. Further, the portion left uncauterized, which may be relatively thick, will possibly not be able to be cut off mechanically.